TECHTOP TD20 Series Product Manual page 115

TD20 Series VFD Communication Protocol
Continuous Parameters
VFD Byte
Data 10s 20s
CRC check
writing
address
address number
number
command
If the response message is as below:
Continuous
VFD
Parameters
Data
CRC check
writing
address
address
number
command
Note: The space between above commands is for instruction and there is no space between the
commands during actual applications.
Common communication fault
Common communication faults: no response to the communication or the VFD returns abnormal fault.
The possible reason for no response to the communication:
Selecting wrong serial interface, for example, if the converter is COM1, selecting COM2 during the
communication
The baud rate, digital bit, end bit and check bit are not the same with the VFD + and - of RS485 are
connected in reverse.
The 485 wire cap on the terminal board of the VFD is not plug in. the wire cap in behind the terminal
arrangement.
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